Looptools - cancel not working
From your video, it seems you have a problem with your hotkeys. CTRL-Z for you is activating the Select More command, which the default hotkey is CTRL-numpad+
Check your keymap, type in &quot;select more&quot; into the search bar and check what it is mapped to. Since you're new to Blender, it might simply be easier to reset your keymapings to default.